The present invention relates to gas springs, and more particularly, to adjustable or variable speed gas springs that have an adjustable extension velocity and that are particularly suited for use as a part of a door closure mechanism where the spring extension velocity determines the closing speed of the door.
In the past, adjustable speed springs of various constructions have been used for a variety of purposes including serving as parts of door closure mechanisms. The adjustment of the shaft extension velocity or speed of springs, which are used as parts of door closing mechanisms, has been achieved by rotating the spring shaft relative to its tubular body or "tube". Those working in this art have long sought to develop springs whose shaft extension speed can be readily and easily adjusted while minimizing the cost of manufacturing the spring. Additionally, a further goal of those working in this art has been to develop an adjustable speed gas spring that will stand up to the forces imposed upon the spring during its usage such as when it is used as a part of a door closure mechanism, that can achieve a full range of speed adjustments within one revolution of the spring shaft relative to its tubular body, and that will be fully functional regardless of the particular orientation of the spring in its use environment.